Rack accommodation device

ABSTRACT

An example rack accommodation device includes a base capable of supporting supporters on a plurality of stages in a first direction and in a plurality of rows in a second direction across the first direction. The supporters are each configured to hold a rack capable of holding a plurality of upright sample holders each accommodating a sample. A first movement mechanism is configured to move the supporters in the first direction, and a second movement mechanism is configured to move the supporters in the second direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2012-111562, filed May 15, 2012, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments relate to a rack accommodation device configured to accommodate a plurality of sample holders.

2. Description of the Related Art

In loading sample holders that accommodate samples, such as blood, into a processing line, racks are used to stably hold the holders upright in a matrix pattern (for example, Jpn. Pat. Appln. KOKAI Publication No. 2008-076185). For example, the sample holders may be carried into a transport path that leads to a sample processing unit, which performs a biochemical analysis or preprocessing of samples. In this case, a rack base is installed beside the transport path, a plurality of racks are arranged and held on the rack base, and the sample holders are sequentially carried into the transport path by a transfer mechanism. In general, a rack base is constructed so that a plurality of racks can be placed side by side on its top portion that is flush with the processing line.

The rack base to carry a large number of sample holders thereon should be increased in size, requiring a larger processing space. In addition, sequential replacement of the racks on the rack base requires complicated operations.

BRIEF SUMMARY OF THE INVENTION

According to an embodiment, a rack accommodation device includes, a base capable of supporting supporters on a plurality of stages in a first direction and in a plurality of rows in a second direction across the first direction, the supporters each being configured to hold a rack capable of holding a plurality of upright sample holders each accommodating a sample, a first movement mechanism configured to move the supporters in the first direction, and a second movement mechanism configured to move the supporters in the second direction.

Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a perspective view of a rack accommodation device according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram of the rack accommodation device of the embodiment;

FIG. 3 is an explanatory diagram of the rack accommodation device of the embodiment;

FIG. 4 is an explanatory diagram of a rack tray according to the embodiment;

FIG. 5 is a perspective view of a rack according to the embodiment;

FIG. 6 is an explanatory diagram showing an operation of the rack accommodation device of the embodiment;

FIG. 7 is an explanatory diagram showing an up-and-down motion of the rack accommodation device of the embodiment; and

FIG. 8 is an explanatory diagram showing a transfer process for the rack accommodation device of the embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The following is a description of a rack accommodation device 1 according to a first embodiment of the present invention. FIGS. 1, 2 and 3 are a perspective view, side view, and plan view, respectively, of the rack accommodation device. In these drawings, some structural elements are enlarged or reduced in scale or omitted for ease of illustration, and arrows X, Y and Z indicate three orthogonal directions, individually. Specifically, the arrows X, Y and Z indicate a transverse direction (second direction), longitudinal direction (third direction), and vertical direction (first direction), respectively, of the device.

The rack accommodation device 1 comprises a base 10, first movement mechanism 30, and second movement mechanism 40. The base 10 serves as a base structure that accommodates a plurality of rack trays 20 for use as supporters configured to hold a plurality of racks 50 each. The first and second movement mechanisms 30 and 40 serve to move the rack trays 20 in the first and second directions, respectively. This rack accommodation device 1 is set in, for example, a loading section of a transport line and used to sequentially load sample holders into the transport line.

The base 10 comprises, for example, a bottom wall 11, a pair of sidewalls 12 and 13, front wall 14, and rear wall 15 and has the form of an open-topped cuboid box. The base 10 can accommodate therein ten rack trays 20, arranged in two rows in the X-direction and on five stages in the Z-direction. In the description of the present embodiment to follow, the row on one side (left-hand side in FIG. 3) in the X-direction will be referred to as a descending row, and the row on the other side (right-hand side in FIG. 3) as an ascending row.

The front wall is formed with a plurality of openings 14 a through which the rack trays 20 can be individually drawn out of the device. Although the front wall is partially opened according to the embodiment, the front side may alternatively be fully open.

A lowering mechanism 30A as the first movement mechanism that serves to hold and lower the rack trays 20 on the stages arranged along the descending row on the one side is provided on the inner surface of the one sidewall 12. A raising mechanism 30B as the first movement mechanism that serves to hold and raise the rack trays 20 on the stages arranged along the ascending row on the other side is provided on the inner surface of the other sidewall 1.

An upper shift mechanism 40A as the second movement mechanism that serves to move the rack trays 20 on the uppermost stage in the ascending row from the other side to the one side is provided at each of the front and rear parts of the top of the base 10. The front and rear upper shift mechanisms 40A are configured to operate in synchronism with each other.

A lower shift mechanism 40B as the second movement mechanism that serves to move the rack trays 20 on the lowermost stage in the descending row from the one side to the other side is provided at each of the front and rear parts of the bottom of the base 10. The front and rear lower shift mechanisms 40B are configured to operate in synchronism with each other.

The rack tray 20 shown in FIG. 4 comprises a base tray 21 supported by the base 10 and a slide tray 22 longitudinally slidable relative to the base tray 21. The base tray 21 comprises a longitudinally elongated, rectangular bottom wall 21 a and a pair of sidewalls 21 b rising individually from the left and right sides of the bottom wall 21 a and has an open-topped, U-shaped cross-section.

The bottom wall 21 a is formed with rectangular plate-like engaging lugs 21 c as first engaging portions that project in the X-direction. The engaging lugs 21 c are disposed at, for example, two longitudinal spots on the axially opposite sides and form engaging plates extending along an XY-plane. Transversely projecting engaging plates 21 d are formed individually at the front and rear end portions of the sidewalls 21 b. Each plate 21 d extends along an XZ-plane and is formed with an engaging hole 21 e for use as a second engaging portion into which an engaging protrusion 42 a can be inserted in the Y-direction.

The slide tray 22 comprises a bottom wall 22 a, a pair of sidewalls 22 b, left and right, and a plurality of rising walls 22 c upwardly rising from the front, rear, and intermediate parts of the bottom wall 22 a and is open-topped. The slide tray 22 is guided for reciprocation in the longitudinal direction (Y-direction) on the base tray 21 and can be drawn out of the base 10 through its corresponding opening 14 a. Each pair of racks 50 are placed on the slide tray 22 with the intermediate rising wall 22 c between them so that their bottom parts are stably supported. A drawer handle 22 d is formed on the front part of the slide tray 22.

The rack 50 shown in FIG. 5 is configured so that a top plate 51, middle plate 52, and bottom plate 53 that are disposed opposite and spaced apart from one another are coupled by a plurality of connecting rods 54. Fifty holder insertion holes 51 a and 52 a, ten in each column and five in each row, are formed as a matrix of holes in the top and middle plates 51 and 52, while fifty holder-end receiving recesses 53 a are formed in a matrix pattern in the bottom plate 53. Sample holders 60 are inserted into the holes 51 a and 52 a so that their respective bottoms are supported by the receiving recesses 53 a of the bottom plate 53. In this way, a large number of sample holders 60 can be stably held upright.

The sample holders 60 are test tubes, i.e., transparent, bottomed cylindrical vessels, such as vacuum blood collection tubes that contain blood, serums, or the like. A detachable cap 61 is attached to the top opening of each sample holder 60. A label 62 printed with a barcode and characters that represent various data, such as identification information on the sample, is affixed to the flank of each sample holder 60.

As shown in FIGS. 1 and 2, the lowering and raising mechanisms 30A and 30B are disposed on the left and right sidewalls, respectively. The mechanisms 30A and 30B are constructed in the same manner. Only the lowering mechanism 30A is shown in FIG. 2. FIG. 2 shows state <S3> in FIG. 6. For ease of illustration of the structure of the lowering mechanism 30A, the second to fourth rack trays 20 from top, racks 50, and sample holders 60 are not shown in FIG. 2, and only the uppermost rack tray 20 and rack 50 are shown.

The lowering and raising mechanisms 30A and 30B comprise a pair of lift frames 32, lift actuator 33, propelling actuators 34, retaining frames 35, and propelling actuators 36. The lift frames 32 are guided for reciprocation in the Z-direction by rails formed individually on the sidewalls 12 and 13 and extending in the Z-direction. The lift actuator 33 serves to raise and lower the lift frames 32. The propelling actuators 34 serve to move the lift frames 32 in the Y-direction. The retaining frames 35 are opposed individually to the opposite sides of the lift frames 32. The propelling actuators 36 serve to move the retaining frames 35 in the Y-direction.

The lift actuator 33 is disposed in the center between the sidewalls 12 and 13 and comprises an output shaft 33 a that projects upward. A junction 37 extending in the Y-direction is connected to the distal end of the output shaft 33 a, and a pair of connecting plates 38 are connected individually to the opposite sides of the junction 37 in the Y-direction. The propelling actuators 34 are connected to the connecting plates 38, individually, and the lift frames 32 to respective output shafts 34 a of the propelling actuators 34, individually. The lift frames 32 are driven by the lift actuator 33 to reciprocate by a predetermined distance in the Z-direction, and it is driven by the propelling actuator 34 to reciprocate in the Y-direction.

The lift frames 32 ascend and descend within the range of a single difference in level that depends on each space between the rack trays 20. Also, the lift frames 32 move in the Y-direction between a retaining position where the engaging lugs 21 c of the rack trays 20 are held individually in retaining recesses 32 a and a retracted position where the lugs 21 c are disengaged from the recesses 32 a.

The two lift frames 32 are plates extending along the Z-direction and that are arranged parallel to each other. The retaining recesses 32 a configured to hold the engaging portions are formed individually in the respective end portions of the lift frames 32 in the Y-direction. Each retaining recess 32 a is in the form of, for example, a notch having a U-shaped opening in its outer edge portion in the Y-direction. Each lift frame 32 has five such retaining recesses 32 a arranged at regular intervals in the Z-direction. As the engaging lugs 21 c individually get into the retaining recesses 32 a, the rack trays 20 are held by the lift frames 32, whereupon the engaging lugs 21 c get out of the retaining recesses 32 a, thereby releasing the hold.

The pair of retaining frames 35 are individually located opposite the opposite sides of the lift frames 32 in the Y-direction. The two retaining frames 35 are extending along the Z-direction and that are arranged parallel to each other. The retaining recesses 35 a configured to hold the engaging portions are formed individually in the respective inner end portions of the retaining frames 35 in the Y-direction. Each retaining frame 35 is in the form of, for example, a notch having a U-shaped opening in its inner edge portion in the Y-direction. The rack trays 20 are individually held by the retaining recesses 35 a.

The retaining recesses 32 a of the lift frames 32 and the retaining recesses 35 a of the retaining frames 35 are arranged at regular intervals and opposite one another. Four such retaining recesses 35 a of each retaining frame 35 are vertically arranged in parallel with one another at regular intervals, and the five retaining recesses 32 a of each lift frame 32 are vertically arranged in parallel with one another at regular intervals. The lift frames 32 in an upper position can hold the rack tray on the uppermost stage by means of the uppermost retaining recesses 32 a. When in a lower position, the lift frames 32 can hold the rack tray on the lowermost stage by means of the lowermost retaining recesses 32 a.

Respective output shafts 36 a of the propelling actuators 36 are connected individually to the retaining frames 35 so that the retaining frames 35 can be reciprocated within a fixed range in the Y-direction by the propelling actuators 36. The retaining frames 35 move in the Y-direction between a retaining position where the engaging lugs 21 c of the rack trays 20 are held individually in the retaining recesses 35 a and a retracted position where the lugs 21 c are disengaged from the recesses 35 a.

The lowering mechanism 30A is disposed on one end side of the device and repeatedly performs a lowering operation at a predetermined timing such that the rack trays 20 stacked on the five stages (at the maximum) in the descending row are collectively held and lowered stage-by-stage. The raising mechanism 30B is disposed on the other end side of the device and repeatedly performs a raising operation at a predetermined timing such that the rack trays 20 stacked on the five stages (at the maximum) in the ascending row are collectively held and raised stage-by-stage.

As shown in FIGS. 1 to 3, each of the shift mechanisms 40A and 40B comprises a pair of rails 41, front and rear, a plurality of sliders 42, shift driver 43, engaging protrusions 42 a, and propelling actuator 44. The sliders 42 are guided for reciprocation by the rails 41, individually. The shift driver 43 serves to move the sliders 42 in the X-direction. The engaging protrusions 42 a serve as engagement retaining portions on the sliders 42. The propelling actuator 44 serves to move the engaging protrusions 42 a in the Y-direction.

The rails 41 span between the sidewalls 12 and 13 in the X-direction, at the front and rear end portions of the base 10, individually. The sliders 42 are engagingly supported for movement by the rails 41. The engaging protrusions 42 a inwardly protrude in the Y-direction from the inside of the sliders 42 in the Y-direction. The engaging protrusions 42 a can be driven by the propelling actuator 44 to move between a retaining position where they are held individually in the engaging holes 21 e of the rack trays 20, thereby retaining the rack trays 20, and a retracted position where they are disengaged from the holes 21 e, thereby releasing the hold.

The upper shift mechanisms 40A are arranged individually at the opposite end portions of the top of the device in the Y-direction. Under the control of a controller 70, the upper shift mechanisms 40A advance the engaging protrusions 42 a so that the protrusions 42 a are inserted individually into the engaging holes 21 e, thereby retaining the uppermost rack tray 20. As the sliders 42 are moved in the X-direction in this retained state, the rack tray 20 is moved from the ascending row to the descending row so that the engaging protrusions 42 a are retracted to release the hold, whereupon the sliders 42 are moved in the X-direction to be returned to their original positions. This series of top shifting operations is repeatedly performed at predetermined timings. The front and rear upper shift mechanisms 40A operate in synchronism with each other.

The lower shift mechanisms 40B are arranged individually at the opposite end portions of the bottom of the device in the Y-direction. Under the control of the controller 70, the lower shift mechanisms 40B advance the engaging protrusions 42 a so that the protrusions 42 a are inserted individually into the engaging holes 21 e, thereby retaining the lowermost rack tray 20. As the sliders 42 are moved in the X-direction in this retained state, the rack tray 20 is moved from the descending row to the ascending row so that the engaging protrusions 42 a are retracted to release the hold, whereupon the sliders 42 are moved in the X-direction to be returned to their original positions. This series of bottom shifting operations is repeatedly performed at predetermined timings. The front and rear lower shift mechanisms 40B operate in synchronism with each other.

The actuators 33, 34, 36 and 44 are connected to the controller 70 so that they are driven under the control of the controller 70. As described later, the rack trays 20 are circulatorily moved and sequentially introduced into a processing area A1 as a plurality of operations, including the reciprocation of the lift frames 32 in the Z-direction, movement of the lift frames 32 in the Y-direction, movement of the retaining frames 35 in the Y-direction, reciprocation of the sliders 42 in the X-direction, and movement of the engaging protrusions 42 a in the Y-direction, are performed individually at predetermined timings.

The operation of the rack accommodation device according to the present embodiment will now be described with reference to FIGS. 6 to 8. FIG. 6 is an explanatory diagram showing a movement operation of the rack accommodation device 1, FIG. 7 is an explanatory diagram showing an up-and-down motion, and FIG. 8 is an explanatory diagram showing a transfer process.

As indicated by arrows in FIG. 6, the rack accommodation device 1 operates in the order of <S1>, <S2>, <S3> and <S4>. Thus, the racks 50 set in the rack trays 20 in the device are sequentially introduced into the processing area A1 as the rack trays 20 are fed counterclockwise and circulated through a predetermined circulatory route by repeating a raising process, transfer process, top shifting process, bottom shifting process, and lowering process in the order named. In the raising process, the ascending row is raised to introduce the rack trays 20 into the processing area A1. In the transfer process, the sample holders 60 are transferred from the processing area A1 on the uppermost stage. In the top shifting process, the rack tray 20 on the uppermost stage after the transfer is slid to the descending row. In the bottom shifting process, the rack tray 20 on the lowermost stage in the descending row is slid to the lowermost stage in the ascending row. In the lowering process, the descending row is lowered by one stage.

[Setting Process]

In a setting process, the slide tray 22 is manually drawn out forward from each of the rack trays 20 in the base 10 and the racks loaded with the sample holders 60 are set. Thereafter, the setting is completed by pushing in the slide tray 22 backward. Thereupon, the racks are held in each rack tray 20 and accommodated in the base 10, as shown in <S1> of FIG. 6. In this embodiment, two racks are set in each of ten rack trays 20, arranged vertically on five stages and horizontally in two rows, and fifty sample holders are set in each rack. In this state, the engaging lugs 21 c of the rack trays 20 individually get into the five-stage retaining recesses 32 a of the lift frames 32 to be supported thereby.

[Raising Process]

In the raising process, the actuators are driven at predetermined timings in the raising mechanism 30B, whereby operations A, B, C, D, E and F are repeated in the order named, as indicated by full-line arrows in FIG. 7. Specifically, the lift frames 32 engaging with the rack trays 20 are raised by one stage (F→A). The retaining frames 35 are advanced to their engagement position such that they engage with the rack trays 20 (A→B). The lift frames 32 are retracted from the engagement position and disengaged (B→C). The lift frames 32 are lowered by one stage and returned (C→D). The lift frames 32 are advanced to their engagement position such that they engage with the rack trays 20 (D→E). The retaining frames 35 are retracted from the engagement position and disengaged (E→F). This series of operations is repeated. In this raising process, the rack trays 20 in the ascending row in state <S1> are collectively raised stage-by-stage. In the raising process, a space is formed at the lowermost stage in the ascending row the moment one of the rack trays 20 is introduced into the processing area A1 on the uppermost stage in the ascending row.

[Transfer Process]

In the transfer process, as shown in FIG. 8, the sample holders 60 are transferred from the rack tray 20 located in the processing area A1 on the uppermost stage in the ascending row to a sample processing line 90 located beside the device by, for example, a transfer mechanism 80.

The transfer mechanism 80 shown in FIG. 8 is located, for example, beside the base 10 and has the function of introducing the sample holders 60 in the racks 50 one by one or in batches of two or more. The transfer mechanism 80 comprises a holder grab 81, grab raising actuator 82, and motor-driven chain mechanism 83. The holder grab 81 comprises a plurality of open/close claws capable of simultaneously grasping a plurality (for example, ten) of adjacent sample holders 60 loaded with samples and an actuator configured to open and close the claws. The grab raising actuator 82 serves to raise and lower the holder grab 81. The chain mechanism 83 serves to transversely move an actuator grab unit, which comprises the holder grab 81 and grab raising actuator 82, at right angles to a transport path, slidingly guided by a traverse guide.

The sample processing line 90 comprises, for example, two belt conveyors 92 and two guide rails 93 extending along a transport channel. Empty sample holders 100 are set on the transport channel and fed in succession.

Each holder 100 comprises a columnar substrate formed by, for example, resin molding. The substrate is formed with an accommodation section, which opens upward at its axial section. A plurality of holder guides are arranged on the inner peripheral surface of the accommodation section. The holder guides are urged by urging means, such as springs, so that they can be displaced to increase or decrease the inner diameter of the accommodation section. Each sample holder 60 is surrounded by the holder guides so that it is vertically held in the accommodation section.

The transfer mechanism 80 serves to insert the sample holder 60 removed from the rack 50 into the empty sample holder 100. The sample holders 60 held in the holder 100 are intermittently transported downstream relative to the transport channel at regular intervals and delivered to various processing devices that are arranged along the transport channel.

[Top Shifting Process]

In the top shifting process, the engaging protrusions 42 a are projected by the propelling actuator 44 and inserted into the engaging holes 21 e of the rack tray 20, thereby retaining the rack tray 20. The sliders 42 are moved in the X-direction along the rails 41 to the uppermost stage of the descending row. The engaging protrusions 42 a are retracted and removed from the engaging holes 21 e by the propelling actuator 44, thereby releasing the hold. The sliders 42 are moved and returned along the rails 41 to the other side. The rack tray 20 holding the empty racks 50 after the transfer is moved to the descending row by repeating this series of operations at predetermined timings.

[Bottom Shifting Process]

In the bottom shifting process, the engaging protrusions 42 a are projected by the propelling actuator 44 and inserted into the engaging holes 21 e of the rack tray 20, thereby retaining the rack tray 20. The sliders 42 are moved in the X-direction along the rails 41 to the lowermost stage of the ascending row. The engaging protrusions 42 a are retracted and removed from the engaging holes 21 e by the propelling actuator 44, thereby releasing the hold. The sliders 42 are moved and returned along the rails 41 to the one side. The rack tray 20 on the lowermost stage in the descending row is sequentially moved to the lowermost stage in the ascending row by repeating this series of operations at predetermined timings.

[Lowering Process]

In the lowering process, the actuators are driven at predetermined timings in the lowering mechanism 30A, whereby the operations A, F, E, D, C and B are repeated in the order named, as indicated by broken-line arrows in FIG. 7. Specifically, the lift frames 32 located in the engagement position and engaging with the rack trays 20 are lowered by one stage (A→F). The retaining frames 35 are advanced to the engagement position such that they engage with the rack trays 20 (F→E). The lift frames 32 are retracted from the engagement position and disengaged (E→D). The lift frames 32 are raised by one stage and returned (D→C). The lift frames 32 are advanced to the engagement position such that they engage with the rack trays 20 (C→B). The retaining frames 35 are retracted from the engagement position and disengaged (B→A). All the rack trays 20 are lowered stage-by-stage by repeating this series of operations. The raising process by the raising mechanism 30B and the lowering process by the lowering mechanism 30A are different only in the order of operations and resemble in content. Therefore, FIG. 7 is used as a common explanatory diagram.

By repeating the raising, transfer, top and bottom shifting, and lowering processes, the rack trays 20 holding the racks 50 carrying the sample holders 60 therein are sequentially introduced into the processing area A1 so that the rack trays 20 holding the empty racks 50 can be sequentially put away into the base. When all the racks 50 are emptied, for example, each rack tray 20 is drawn out forward, and the empty racks 50 are replaced with loaded racks 50.

The following effects can be obtained according to the rack accommodation device 1 of the present embodiment. The processing space can be reduced by storing a large number of racks 50 in a plurality of rows and stages. By sequentially feeding the racks along the predetermined circulatory route, moreover, the frequency of rack replacement can be reduced, that is, the working efficiency can be improved.

Further, the rack trays 20 are stacked in a plurality of stages in the first direction, based on the descending and ascending rows on the one and the other sides in the second direction, so that efficient processing can be achieved based on simple movement processing. Furthermore, the racks 50 can be easily set and replaced, taking advantage of the structure of the rack trays 20 that can be drawn out in the third direction.

The present invention is not limited directly to the embodiment described herein, and in carrying out the invention, its constituent elements may be embodied in modified forms without departing from the spirit of the invention. Although the transfer mechanism is used for loading according to the foregoing embodiment, for example, it may alternatively be used in various other devices.

According to the embodiment described above, for example, the racks 50 loaded with the sample holders 60 are set and sequentially introduced into the processing area A1 and carried from the processing area A1 into another transport line. Then, the empty racks 50 are re-accommodated. Alternatively, however, empty racks 50 may be first set and sequentially introduced into the processing area A1 so that the sample holders 60 can be externally transferred to the empty racks 50 in the processing area A1, for example. If this is done, the racks 50 can be used for unloading from the predetermined transport line by re-accommodating the racks 50 loaded with sample holders 60.

According to the embodiment described above, moreover, the sample holders 60 are transferred from the racks 50 in the processing area A1, and the empty racks 50 are accommodated. Alternatively, however, the racks 50 sequentially introduced into the processing area A1 may be individually transferred to another transport line or processing device, for example. Also in this case, the rack trays 20 are circulated so that the racks 50 can be sequentially introduced into the processing area A1. After the racks 50 are transferred to another transport line, the empty rack trays 20 are returned to the device so that new racks 50 can be set in the empty rack trays 20 at predetermined timings. Thus, the same effects as those of the foregoing embodiment can be obtained. Further, this arrangement is applicable to various other systems in which a large number of racks 50 and sample holders 60 held therein are processed in succession.

Furthermore, the shift and lift mechanisms are not limited to the structures described in connection with the foregoing embodiments, and various other structures are applicable.

In addition, the constituent elements described in connection with the foregoing embodiments may be deleted or their shapes, structures, materials, etc., may be changed. Various inventions may be made by suitably combining a plurality of constituent elements described in connection with the foregoing embodiments.

Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. 

What is claimed is:
 1. A rack accommodation device comprising: a plurality of supporters a base having a first side and a second side capable of supporting the plurality of supporters on a plurality of stages in a first direction and in a plurality of rows in a second direction across the first direction, the supporters each being configured to hold a rack capable of holding a plurality of upright sample holders each accommodating a sample; a first movement mechanism configured to move the supporters in the first direction; and a second movement mechanism configured to move the supporters in the second direction, wherein the first movement mechanism comprises a raising mechanism configured to raise the supporters on the plurality of stages in an ascending row on the first side and a lowering mechanism configured to lower the supporters on the plurality of stares in a descending row on the second side, the second movement mechanism comprises an upper shift mechanism configured to move the supporters on an upper stage in the ascending row to the second side and a lower shift mechanism configured to move the supporters on a lower stare in the descending row to the first side, the supporters are moved along a predetermined circulatory route such that the racks are sequentially introduced into a predetermined processing area, each of the supporters comprises a slide tray capable of being drawn out of the base in a third direction across the first and second directions, each of the supporters comprises first engaging portions engaged by the raising mechanism and the lowering mechanism and second engaging portions engaged by the upper shift mechanism and the lower shift mechanism, each of the first engaging portions including at least two sets of engaging lugs, a lift actuator capable of moving in the first direction, the raising mechanism and the lowering mechanism each comprise a retaining flame capable of reciprocating by means of one propelling actuator between a position for engaging with one set of engaging lugs on the first engaging portions of the supporters and a retracted position for disengaging from the one set of engaging lugs on the first engaging portions, and a lift flame capable of reciprocating by means of another propelling actuator between a position for engaging with another set of engaging lugs on the first engaging portions of the supporters and a retracted position for disengaging from the another set of engaging lugs on the first engaging portions and of an up- and-down motion by means of the lift actuator, the upper shift mechanism and the lower shift mechanism each comprise a slider, comprising an engagement retaining portion capable of reciprocating between a position for engaging with the second engaging portions of the supporters and a retracted position for disengaging from the second engaging portions, and a shift driver configured to move the slider in the second direction, a controller controls the operations of the raising mechanism, the lowering mechanism, the upper shift mechanism, and the lower shift mechanism so that the supporters are held, moved, and disengaged at predetermined timings and moves the supporters along the circulatory route, and wherein a transfer mechanism is configured to transfer the sample holders held by the rack in the processing area to a predetermined transport line. 